What is it that makes Superman Super? And
is there any basis in 'real' science for the man of steel?

by Lois Gresh and Robert Weinberg

When we examine Superman, we need to
remember that, in a sense, we’re examining all the superheroes
who follow. Superheroes have always been created with broad brushstrokes.
Not a lot of time was spent on deducing the limits or nonlimits
of our super characters. Even less attention was paid to their interaction
with ordinary people and objects. ‘When Superman lifts a car
over his head to shake criminals to the ground, no one ever questions
why the car doesn’t fall to pieces. Nobody questions how Superman
stays perfectly balanced on Earth while waving over his head an
item that has a mass twenty times greater than his own.

How often have we seen Superman fly
down and pull a car up by the roof into the sky? In the real world,
there are few vehicles that would even hold together if Superman
yanked them up by the roof. The car would probably continue forward,
with the roof ripped off and held by Superman. Every time Superman
lifts a building into the air, why don’t all the bricks, held
together by cement and pressure, suddenly start falling apart? Those
are the types of ordinary problems that seem never to occur in any
superhero adventures. Basically, superheroes perform super acts
and the logic squad cleans up afterwards.

In Superman’s first appearance
in the 1938 Action Comics, we’re informed “that he could
leap one-eighth of a mile; hurdle a twenty-Story building . . .
raise tremendous weights . . . run faster than an express train
. . . and that nothing less than a bursting shell could penetrate
his skin!”

Siegel and Shuster’s explanation
of Superman’s powers, as given in Action Comics #1, left much
to the imagination. Their main premise was that Superman came from
a civilization much more advanced than ours and thus the inhabitants
were physically more advanced than humans. By extrapolation, this
argument implies that modem man is physically much stronger than
Cro-Magnon man or Neanderthal man. Of course, our ancestors lived
only a few hundred centuries before us, while Superman’s race
was described as being millions of years ahead of ours. A full-page
illustration in Superman #1 (Summer 1939) gave a “scientific
explanation of Superman’s amazing strength.”

“Superman came to Earth from the planet Krypton, whose inhabitants
had evolved, after millions of years, to physical perfection. The
smaller size of our planet, with its slighter gravity pull, assists
Super-man s tremendous muscles in the performances of miraculous
feats of strength.”

Thus, Siegel and Shuster gave two explanations for Superman’s
extraordinary powers. He was an alien from a planet not in our Solar
System, and the weak gravity of Earth compared to the gravity of
his home world of Krypton gave him amazing strength. Both concepts
came right from the pages of science fiction magazines of the time,
and few readers questioned the logic of either assumption.

Could this
have been the way Superman escaped from the Planet Krypton?

Let’s assume Superman could indeed
come to Earth. What powers would he possess that would make him
a superman when compared to humans?
Going back to the original Superman of Action Comics #1, it’s
clear he has tremendous strength and can jump great distances, but
he never flies. In Superman #4, for example, he runs from Metropolis
to Oklahoma. Siegel and Shuster created a character they thought
was believable based on the science of the time.

There was no explanation for flight, so the best Superman could
do was jump.
As the years passed and competition increased, Superman’s
powers grew as his creators continued to change the character to
meet the demands of an ever-increasing audience. By 1943, Superman
could fly at speeds faster than light (another impossibility). Needless
to say, as his powers grew more incredible, so did his strength.
In early issues of Action Stories, Superman lifts an automobile
over his head. Within a few years, he’s carrying buses packed
with astonished riders. After a few more years, he’s carrying
ocean liners. By the 1960s, he’s moving planets.

Siegel and Shuster’s original comic book concept was that
Super-man’s tremendous strength was the result of being born
on a high-gravity planet. Earth’s gravity was much weaker
than that of Krypton, so Superman was able to lift heavy objects
due to the difference in gravitational fields.

"Everyone knows that Superman is a being
from another Planet, unburdened by the vastly weaker gravity of
Earth. But not everyone understands how gravity affects strength!
If you were on a world smaller than ours, you could jump over high
buildings, lift enormous weights . . . and thus duplicate some of
the feats of the Man of Steel!"

Which leads to our second basic question
about Superman: How strong must Krypton’s gravity have been
to endow Superman with such incredible strength? Answering this
question requires we first answer another: How massive was the planet
Krypton that it had such high gravity?

Superman appears to weigh approximately
100 kg (220 lbs). An athlete in top physical condition can lift
his own body weight. Running and throwing a heavy object might not
be so easy. For our study, we’re going to assume that Superman
is 1,000 times stronger than an ordinary Earthman. That would mean
he could lift 100,000 kg or approximately 220,000 pounds. This is
approximately the weight of three filled semi-trailer trucks or
a DC-9 airplane without fuel or passengers. Cranes used to construct
bridges can handle about that weight, so we’d have a Superman
still well within the bounds of human imagination. Such strength
would even enable him to leap a mile with one jump, thus approximating
flying in the eyes of most people.

The force necessary to lift an object on a planet is equal to the
mass of the object multiplied by the gravitational force present
on that planet. Thus, a human who could lift 100 kg on Earth could
lift 600 kg on the Moon, which has one-sixth the gravity of Earth.
Which would imply that for Superman to be 1,000 times stronger on
Earth than he is on Krypton, Krypton would have to be 1,000 times
as massive as the Earth.

Earth’s gravity is 9.8 meters/sec
squared, or for simplicity’s sake, 10 meters/sec squared;.
Multiplying that number by 1,000 gives us the gravity of Krypton,
10,000 meters/sec squared.

Could a planet exist with such a gravitational field? According
to Brother Guy Consolmagno of the University of Arizona, a planet
with even fifty times the gravity of Earth “is essentially
impossible to construct, given the physics of solid matter as we
understand it.”

Put in even simpler terms, “a body with . . . a surface gravity
of 10,000 in/sec squared would have a mass of 6 x 1033kg ..., which
would be 3,000 times the mass of the sun.”

According to the basic laws of physics, Krypton is impossible. Moreover,
for people resembling us to live on Krypton, they’d need muscle
and bones 1,000 times stronger than human muscle and bone. No such
material exists to create bone or muscle, or the complex internal
organs necessary for life as we know it.

On a planet with gravity 1,000 times
that of Earth, would it be possible to send a rocket ship, especially
a small one as seen in numerous issues of Superman and Action Comics,
to Earth? The escape velocity (the speed necessary to break the
gravitational pull of a planet) of Krypton would be enormous, approximately
11,000 km/second. That’s about 1/30 the speed of light. No
chemical reaction in the universe could produce enough energy necessary
to achieve such velocity.

In the 1960s, the explanation for
Superman’s powers was revised: his super strength, ability
to fly, and more came not only from the high gravity of Krypton
but also from growing up under a yellow sun instead of a red one.
Unfortunately for Superman, light is light. The light from a red
sun would merely have a smaller occurrence of high frequencies than
the light from a yellow sun. Infrared light would be more common,
but that’s about it. Red star or yellow star, Super-man’s
powers would be the same.

Superman is one of the most fascinating characters in comic books,
and he’s one of the most recognizable characters on Earth.
He’s one of those people we wish could exist, but doesn’t.
Visitors from other planets are possible. Superman’s not.